The present invention relates generally to isolation manifolds for use with industrial processes. In particular, this invention relates to isolation manifolds for use with pressure transmitters.
Pressure transmitters are used to monitor the pressure of process fluids used in industrial processes. A pressure transmitter includes a pressure sensor that produces an electrical output as a function of the pressure of a process fluid, such as water lines, chemical tanks or the like. Each pressure transmitter also includes transmitter electronics for receiving and processing the electrical output of the sensor so that the transmitter and process parameter can be monitored locally or remotely. Locally monitored transmitters include displays, such as LCD screens, that show the electrical output at the site of the process transmitter. Remotely monitored transmitters include electronics that transmit the electrical output over a wired control or monitoring loop or wireless network to a central monitoring location such as a control room. Configured as such, the process parameter can be regulated from the control room by including automated switches, valves, pumps and other similar components in the control loop.
Pressure transmitters may be connected to the process to be monitored by an isolation manifold. An isolation valve (or block valve) in the manifold can be closed to isolate the pressure transmitter from the process for service (e.g. calibration) or removal of the pressure transmitter. Isolation manifolds may also include a bleed port to relieve any pressure in the manifold prior to servicing or removing the pressure transmitter. Typically, the bleed port includes a bleed screw or a bleed valve operable to selectively open or seal the bleed port. Isolation manifolds including an isolation valve and a bleed port are also referred to as block and bleed manifolds.